A liquid crystal display comprises a polarizing plate and a liquid crystal cell.
A TFT (thin film transistor) liquid crystal display of TN (twisted nematic) mode, which is mainly used, further comprises an optical compensatory film provided between the polarizing plate and the liquid crystal cell. As described in Japanese Patent Provisional Publication No. 8(1996)-50206, the optical compensatory film enables the display to give an image of high quality. However, on the other hand, the compensatory film makes the display thick.
Japanese Patent Provisional Publication No. 1(1989)-68940 discloses a liquid crystal display in which an optical compensatory sheet (phase retarder) is provided on one surface of the polarizing plate and an elliptically polarizing plate having a protective film is provided on the other surface. Because of this structure, the front contrast is improved without thickening the display. However, the optical compensatory sheet is often thermally distorted to change the phase retardation, so that a displayed dark image is framed with leaked light. Consequently, the display has poor durability.
In order to improve the durability without thickening the display, Japanese Patent Provisional Publication No. 7(1995)-191217 and European Patent No. 0,911,656A2 disclose that an optical compensatory sheet comprising a transparent support and a thereon-provided optically anisotropic layer comprising a discotic compound is directly adopted as a protective film on the polarizing plate. For forming the optically anisotropic layer, a coating solution comprising the discotic compound is applied on the support.